9 Things you Didn't Know About Swimming Detraining

Swimming Detraining: 9 Things you Didn’t Know!

admin Blog, Dr. John Mullen, Latest&Greatest, Training 4 Comments

“What are you doing during the shelter-in-place?” “Is your team practicing?” “Anyone have any Zoom practice ideas?” These are the common questions from coaches and swimmers. Clearly, coaches and swimmers are concerned about swimming detraining. 

I recently spoke with Dr. Rodrigo Zacca, Ph.D, a Postdoctoral Researcher of Universidade do Porto, Porto, Portugal who published a recent study on Effects of detraining in age-group swimmers performance, energetics and kinematics. The 7 items are from our written exchange.

9 Things you Didn’t Know about Swimming Detraining

  1. Swimming Impairs: OK, maybe you already knew this one, but the main conclusions of this study suggest that detraining after four-weeks of pool-based training cessation can impair swimming performance at the start of the following training season in age-group swimmers, underlining the importance of maintaining fitness levels during off-season or swimming detraining. 
  2. 3.8% Impairment: The 400-m front crawl performance of 14–15 years old competitive swimmers was impaired by ~3.8% after four-weeks of training cessation, mainly associated with reductions in stroke rate (SR), increase in peak blood lactate concentrations ([La]) and limited non-swimming specific physical activities during this training cessation period. 
  3. No Effects from Growth: Four-weeks was not long enough to detect growth effect on performance, but impairment of 400-m front crawl performance was attenuated by those swimmers who were more physically active during the off-season.
  4. Elite Swimmers 4-Week Detraining: For elite swimmers, there are three interesting studies. Costill et al. (1985) brought us valuable information back in the mid-1980s. After 20 weeks of intense training, male swimmers were evaluated during 4 weeks of training cessation. Skeletal muscle oxidative capacity (biopsy from deltoid muscle) decreased by 50% after one week, but remained similar during the subsequent weeks. Muscle phosphofructokinase and phosphorylase activities remained similar. Muscle glycogen gradually reduced. Baseline [La] peak values after swimming 200 yards (~183 m) at 90% of swimmer’s best time was 4.2 ± 0.8 mmol ∙ l -1 , increasing to ~ 9.7 ± 0.8 mmol ∙ l -1 after 4 weeks. Impairments in performance higher [La] peak values were the combined result of a decline in muscle´s respiratory capacity and diminished oxygen transport system.
  5. 3x/week Detraining in Elite Swimmers: Another cool study was performed by Neufer et al. (1987). Following five months of competitive training, three groups of male swimmers performed 4 weeks of either training reduction or cessation. Reduction in swimming training to only 1 ∙ week -1, with ~30% of prior training volume/load (9000 yards ∙ day-1; “intense training”), did not provide enough stimulus to preserve the aerobic power (V̇O2max) in male swimmers. However, reduction in swimming training to only 3 ∙ week -1, with ~30% of prior training loads, results in little or no decrement in V̇O2max. Besides, muscular strength is not impaired over 4-weeks of training reduction or cessation. However, power (biokinetic swim bench system) is impaired in both cases (training reduction or cessation). Despite that, impairments in performance are markedly less when swimmers continue to train even only 3 ∙ week -1 with ~30% of prior training volume/load.
  6. 2 Month Detraining in Elite Swimmers: Finally, the impact of 2-months training cessation (swimming detraining) on diet and body composition was studied by Almeras et al. (1997) in elite female swimmers. The authors observed that body weight gain (4.8-kg) and body fat gain (~ 4 kg of fat mass) occurs in response to training cessation.
  7. High-Intensity Maintains Performance: Non-swimming specific physical activities during the offseason or swimming detraining accounted for 40% of the total variance in performance, showing good partial correlation with impairment in performance. Low intensity non-swimming specific physical activities during the off-season, isolated, did not account for much of the total variance in performance. Moderate intensity non-swimming specific physical activities accounted for 31% of the total variance in performance, but partial correlation with impairment in 400-m front crawl performance was not significant. However, vigorous intensity non-swimming specific physical activities during the off-season accounted for 42% of the total variance in performance and showed good partial correlation with the impairment in 400-m front crawl performance.  The take-home message is clear, age-group swimmers should be physically active when enjoying the off-season, undertaking mainly moderate and vigorous activities. For example, swim ergometers and even running or cycling for aerobic conditioning, and dryland workouts (such as dry land sports, cross-training or gym-based exercises, listen to what World Championships team member Margo Geer is doing during Covid-19) could be helpful in minimizing impairments in swimming performance during the transition to the following competitive season. If you are looking for high-intensity dryland, checkout the Swimming Science Dryland Squad.  
  8. How Long to Get In Swimming Shape After Covid-19: Many factors will influence the length of time for recovery from Covid-19. Size and speed to reverse these losses after the #Covid19 will depend on many aspects, such as current fitness level, training history, age, specificity of previous training, and even genetics (Mujika and Padilla 2000; Abrahin et al. 2019). However, since the pandemic is not over yet and we do not know when it will end, it’s time to attenuate the impairments in performance. Those who manage to remain more active (in a creative and intelligent way) will have fewer problems after this pandemic period.
  9. Other Tips on Limiting Impairments from Swimming Detraining: First, don’t stand waiting for the end of pandemic, as the impairments can be irreversible. Even small amounts of training can help at this stage, so keep working. Second, be creative to create alternatives, but be intelligent (specificity matters a lot). Volume and intensity progression must be balanced and according to the current state of each swimmer (so, test the variables that are relevant, basically those that are likely to be tested in these difficult times). Workouts must be appropriate to the swimmer’s chronological and biological age; It is also crucial to document all swimmers’ development; Focus in recruitment of motor units, motor patterns, muscle synergies, coordination, strength, power and endurance. At this moment it is essential that swimmers have support from clubs, being guided by qualified professionals for these issues. It is crucial for the team’s success. Swimmers cannot be adrift … It is necessary to guide and test them even during this period. Otherwise, we will be in a dark room without even a candle to orient ourselves. Besides, we will not be respecting the individuality of the swimmers, we will be working with ‘average values’. This is an excellent opportunity to expand this field of knowledge.

What else do we need to research in regards to Swimming detraining?

In the sport sciences community, I could list:

  • Injury, health and disease problems;
  • Taper;
  • Off-season;
  • … and now a pandemic;

However, swimming detraining research is not exclusive to sport sciences. Much of what we know comes from other areas. Understanding the effects of training reduction and cessation is of interest to other communities and society in general. 

In the Military community…

  • Long trips confined military on aircraft carriers, submarines, etc.

In the aerospace research community…

  • Manned trips (e.g. the much desired human mission to Mars;

In the society…

  • Physical inactivity vs physical or mental health outcomes in older adults;
  • Effects of being bedridden;
  • Maintenance or loss of autonomy (e.g. aging, bone, joint and muscle disorders, paraplegia and quadriplegia).


  1. Costill DL, Fink WJ, Hargreaves M, King DS, Thomas R, Fielding R. Metabolic characteristics of skeletal muscle during detraining from competitive swimming. Medicine & Science in Sports & Exercise. 1985;17(3):339-43.
  2. Neufer PD, Costill DL, Fielding RA, Flynn MG, Kirwan JP. Effect of reduced training on muscular strength and endurance in competitive swimmers. Medicine & Science in Sports & Exercise. 1987;19(5).
  3. Almeras N, Lemieux S, Bouchard C, Tremblay A. Fat gain in female swimmers. Physiology & Behavior. 1997;61(6):811-7.
  4. Zacca R, Toubekis A, Freitas L, Silva AF, Azevedo R, Vilas-Boas JP, Pyne DB, Castro FAS, Fernandes RJ. Effects of detraining in age-group swimmers performance, energetics and kinematics. Journal of Sports Sciences. 2019;37(13):1490-8.
  5. Abrahin O, Cortinhas-Alves EA, Vieira RP, Guerreiro JF. Elite athletes have longer telomeres than sedentary subjects: A meta-analysis. Experimental Gerontology. 2019;119:138-45.
  6. Mujika I, Padilla S. Detraining: loss of training-induced physiological and performance adaptations. Part II: Long term insufficient training stimulus. Sports Medicine. 2000;30(3):145-54.

Written by Dr. GJohn Mullen.

Comments 4

  1. Thank You for this very helpful article! For sure here in Brazil a lot of swim coaches are going in the opposite way…
    In my opinion this may cause some terrible problems specially for age group swimmers…
    I’m taking the liberty to share with others!
    Thank You again,

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